Low vitamin D levels may contribute to symptoms of depression, according to a new study. The research could help to illuminate previous smaller studies' conflicting findings regarding the relationship between vitamin D and depression, the researchers said.

Researchers analyzed information on the vitamin D levels and depressive symptoms of almost 12,600 participants collected from late 2006 to late 2010.

Their findings showed that higher vitamin D levels were associated with a decreased risk of current depression, particularly among people had previously experienced depression.

Correspondingly, low vitamin D levels were associated with having more depressive symptoms, particularly among those with a history of depression. The study's findings, which werepublished in the November issue of the journal Mayo Clinic Proceedings, may aid doctors in accessing the health of patients with depression, the researchers said.

"Our findings suggest that screening for vitamin D levels in depressed patients — and perhaps screening for depression in people with low vitamin D levels — might be useful," study researcher Dr. E. Sherwood Brown, a professor of psychiatry at the University of Texas Southwestern Medical Center in Dallas, said in a statement.

Still, questions remain about the relationship between vitamin D and depression, such as whether low levels of the vitamin contribute to symptoms of depression, or if depression may lower a person's vitamin D levels.

And the study did not address whether increasing vitamin D levels could reduce depressive symptoms.

The findings add to a growing body of research regarding vitamin D's link to depression. A 2008 Netherlands study of 1,282 people between ages 65 and 95 found that older adults with low blood levels of vitamin D had a higher risk of depression. However, a 2009 study of 3,262 people between ages 50 and 70 from Beijing and Shanghai showed no clear link between levels of vitamin D in the blood and depression.

While researchers may continue to debate its role in depression, previous studies have shown that vitamin D may offer several other health benefits. A 2010 study published in the Archives of Neurology found that vitamin D may reduce a person's risk of developing Parkinson's disease, and two recent studies conducted at the Intermountain Medical Center Heart Institute in Murray, Utah, found that supplementing one's diet with extra vitamin D may help lower cardiovascular disease risks.

Pass it on: Low vitamin D levels may contribute to symptoms of depression, but it has not been determined that taking vitamin D supplements will lessen depression.